The Battle of Thermopylae (480 B.C.) is one of history's enduring tales of heroism: 300 Spartans, led by warrior King Leonidas, fought to defend their home against hundreds of thousands of Persian invaders under the control of self-proclaimed god-king Xerxes.

In the hands of Snyder, working from an award-winning graphic novel by comic-book master Frank Miller ("Sin City"), the three days of ferocious combat become larger than life. Modern scholars often put the size of Xerxes' forces at about 250,000; the novel and film prefer the heroically apocryphal 1 million. Persian arrow volleys are so dense they "blot the sky," and their marauding armies include inhuman combatants. It's as if Snyder and Miller want to do for Thermopylae what Homer did for the Trojan War.

"The idea was to create a world you hadn't seen before," says producer Bernie Goldman. "We didn't want to make a historical movie; we wanted to make a movie about the legend."

"300" has epic themes and is played out on an epic scale. In Miller's account, Xerxes is 9 feet tall, a splendid, awe-inspiring creature adorned with ornate gold chains and piercings. Battle elephants are three stories high. Xerxes' elite fighters, the Immortals, owe more to Japanese ninja than Persian tradition. Snyder's version adds "bullet-time" visuals and screaming metal guitars.

"It has grand themes and all that stuff," Snyder says, "but I wanted to make a fun-ride movie for adults, where you could say, 'That's sexy, that's gory.' It's at 11 the entire time.

"I wanted a movie that knew it was a graphic novel. I love Frank. I'm a huge fan, I felt a responsibility to do a cool job with it. But I also felt that the movie should be, in some ways, well, in a lot of ways, transcendent of the genre of swords and sandals. It should be something else."

Before helming the cheeky, caffeine-buzz remake of "Dawn of the Dead" (2004), Snyder was a sought-after commercial director (he has won Clios and a Gold Tiger Award at Cannes). The 41-year-old Green Bay, Wis., native with unkempt hair and a distressed Catalina Grand Prix T-shirt brims with enthusiasm, his words firing in sustained bursts during a meeting at the Beverly Hilton.

"When you get a fantasy film for adults, in recent years, anyway, they're depressing," he says, citing "Children of Men" and "Pan's Labyrinth." "By the way, I love those movies, they're fantastic movies, but they're not a fun ride at the movies. You don't leave them going, 'Yeah! That was awesome!' "

Although "300" and "Sin City" were both shot against virtual backgrounds, their visual similarity ends with Miller's distinctive compositional style. Unlike the flat, two-toned, shadow-heavy appearance of the earlier film, every frame of "300" seems painted, for a more complex, textured look. And it isn't captured by a robotic eye.

"That absolutely was conscious," Snyder says. "I didn't want it to look like it came out of a computer. We shot the movie on film. We added grain because I wanted it to feel like a movie. When you watch (the first battle), there are lens flares, there's a little dirt on the lens -- that's all done in post. Or in a shot when someone's running or something, I would purposely be just a little bit behind. It's made by humans."

Producer Deborah Snyder (Zack's wife) thinks "300" is less of a guys' film than "Sin City" was.

"It deals with freedom, it deals with this event that happened so long ago. It also has a really strong female character," she says. Queen Gorgo, played by Lena Headey, "is the heart of Sparta; she equals Leonidas in her journey. Also, the violence ... it's very beautiful. To me, it's like a ballet of death; it's very operatic. Also, the guys -- I mean, there's a lot to look at."

One of those outrageously ripped "guys" running around in essentially a cape and Speedo (the film's Spartans don't wear armor) is Scottish actor Gerard Butler, who stars as Leonidas. He's not a big name in the United States yet -- his best-known work here is as the title character in "The Phantom of the Opera" -- although he does have previous epic-hero experience in the little-seen "Beowulf and Grendel."

"He doesn't have to say very much, and he just commands your attention on the screen," Goldman says. "That's kind of what makes somebody a king, that presence, that ability to hold a room. ... So few guys have that kind of masculinity, where men can respect them and women can admire them as well. ... I think people will look back on ('300') and say, 'Oh, that's the movie that made Gerry Butler a star.' "

Zack Snyder says Butler simply was Leonidas.

"There's a scene when he says, 'This battle is over when I say it's over!' You look at that scene in the graphic novel, and he looks just like him," he says. "It's weird. It's pretty awesome."

If Miller's work is, as "300" screenwriter Kurt Johnstad says, the "Holy Grail" of the comic world, up next for Snyder is the Ark of the Covenant: Alan Moore's seminal Watchmen series. Snyder says he's dueling with the studio to keep the complex, mind-bending thriller "more 'Strangelove' than 'Fantastic Four.' " While Watchmen presents a bleak political landscape, the very point of view of "300" is debatable.

"Here's what I've had thrown at me, which is awesome," the director says. "I've been asked, 'Is Leonidas an insurgent, or is he George Bush?' I go, 'The fact that you're not clear about it I would hope might generate some healthy conversation about what it means.' Look, if the movie can make that debate real, make people talk about it, great. That's more than I could ever hope."
"300" (R) opens Friday at Bay Area theaters.